This application is based on and claims the priority under 35 U.S.C. xc2xa7119 of German Patent Application 198 40 077.2, filed on Sep. 3, 1998, the entire disclosure of which is incorporated herein by reference.
1. Field of the Invention
The invention relates to an apparatus for packaging of articles or stacks of articles such as letter envelopes, whereby the apparatus simultaneously forms the cartons from precut and precreased blanks.
2. Background Information
It is known to use precut and precreased blanks for making cartons. Such blanks, also referred to as folding box blanks, are initially flat and include the following sections, a bottom section, two side wall sections, a number of end wall sections, and at least one cover section and connector tabs possibly including corner connector tabs. These sections and tabs are interconnected along folding lines, each provided with a respective precrease or indentation. When such a flat blank has been inserted into the carton folding machine, an article or a stack of articles is set onto the bottom section and the side and end wall sections are folded against the article or a stack of articles. More specifically, the side wall and end wall sections and the tabs are folded upwardly or folded over. For this purpose the folding machine has a work support surface for the flat blank and lower and upper tool sections. A lower tool section is positioned in its starting location below the work support surface. The lower tool section is equipped with blank side folding flaps that are displaceable into a working position reaching above the work support surface. These flaps include lateral wall folding flaps, end wall folding flaps, and further folding flaps each provided with respective drives. An upper tool section includes a device for folding over the carton cover and the connector tabs. A further upper tool section such as an adhesive applicator provides adhesive on the folded blank and connector tabs for fixing the sections to one another to finish the box.
German Utility Model Publication DE 92 08 784 U describes an apparatus as described above. In the known apparatus the entire folding operation is performed by a lower tool section which has two side folding plates driven by a common drive. A cover folding flap is journalled to each of the side folding plates. Each cover folding flap is equipped with a respective cover folding flap drive. The end wall sections are lifted up by strikers movable upwardly above the work support surface along a straight upwardly slanted line. Instead of the strikers end wall folding flaps can be used. Stapling devices allocated to the four corner areas of the box are used for fixing the folded blank sections into a box shape. The stapling devices simultaneously lay stapling tabs against the stack to be packaged.
The lower tool section in the known apparatus for packaging letter envelopes is mounted in a fixed position in a machine frame and the folding flaps can only be tilted, but are not position adjustable. As a result, the known apparatus can handle only precut blanks of a predetermined size. This limitation entails another limitation in the size of the articles or stacks of articles to be packaged which is also limited to the given size of the precut blank.
German Patent Publication DE 196 36 262 A1 discloses an apparatus for producing of folding boxes from precut blanks. Four corner folding tools form corner modular units one of which is allocated to each of the four corner points of the bottom section of the blank, for lifting the side wall sections and the end wall sections. These modular units are supported on a rectangular frame including two longitudinal carrier beams and two cross carrier beams. The spacing between the cross beams and the spacing between the longitudinal beams are variable with the aid of laterally positioned adjustment spindles, whereby an adaptation of the apparatus to blanks having bottom sections of different sizes becomes possible. The fixing of the raised lateral and end walls in their box forming positions is accomplished by applying adhesive to respective bonding tabs.
The just mentioned known apparatus is not used for simultaneously packaging articles or stacks of articles. Rather, the folding boxes are formed in the apparatus for a subsequent filling at another location. For this purpose the folding boxes remain first open and accordingly cover folding flaps are not provided. Besides, the known apparatus applies an over-stretching of precut blank flaps which are pressed into the already partly finished box in order to keep these flaps in a lifted position after release of the tools. Thus, it is not possible to further develop the known apparatus in such a way that an article or stacks of articles can be enclosed by the blank as the blank is being folded into a box.
Incidentally, the terms article as used in the following text is intended to mean a single article, a plurality of articles, a stack of articles or a plurality of article stacks.
In view of the foregoing it is the aim of the invention to achieve the following objects singly or in combination:
to improve an apparatus of the type first described above in such a way that an article can be packaged in a folding box blank by simple means in a safe and reliable manner, and so that the folding box blanks may have different sizes and configurations to package articles of different sizes, in boxes of different sizes on the same machine;
to enclose an article in a box already during the folding of the box;
to accommodate various sizes of precut blanks by a simple adjustment of the position of blank folding modular tool units in the folding and packaging machine; and
to allocate box forming functions to a lower tool section while cover forming functions and box section fixing functions are performed by an upper tool section.
The above objects have been achieved according to the invention by a lower tool section that is characterized by four lower modular tool units allocated to the four corner points of a bottom section of a precut carton blank on a work or blank support surface formed by the lower tool section. Each modular tool unit including its folding flaps is mounted in such a way in the lower tool section that the positions of the modular tool units are adjustable in pairs in a longitudinal direction and in a cross direction for adaptation to blank bottom sections of various sizes, and in that the lower tool section with all its modular units is movable by a drive either linearly back and forth on a horizontal guide or rotationally about an axis extending orthogonally to the work support surface or both linearly and rotationally and/or up and down.
By using four corner modular tool units in combination with the position adjustability of these units individually relative to each other the apparatus according to the invention can be adapted to handling precut blanks having bottom sections of different sizes. Further, the linear or rotational movability of the lower tool section, particularly the rotatability or tiltability of the lower tool section, with all its units and components including its work support surface, makes it possible to properly position an unfinished box relative to the upper tool section or sections including a fixing device such as adhesive nozzles for completing the box. According to the invention, it is now possible to selectively supply the precut blanks of different sizes in coordination with the packaging of articles of different sizes. The removal of finished packages in the desired direction has also been facilitated.
Especially the division of the packaging apparatus according to the invention into a lower tool section that forms the box proper and into an upper tool section that forms the box cover has the advantage that the versatility and useability of the apparatus is increased, whereby the present apparatus is useable for various types of packaging operations and various types of packages. Moreover, the entire apparatus becomes less complicated by the division into lower and upper tool sections which are more easily seen and accessible, e.g. for maintenance work. The respective functions of folding the box and forming the cover are also separated whereby the operational safety and the capacity of the apparatus are further improved.
It is especially advantageous if the lower tool section in addition to its rotational motion can be linearly displaced in the machine frame either up and down or back and forth, whereby the work support surface can be properly oriented in the vertical and horizontal directions. The vertical or elevational positioning makes it possible to handle boxes of different heights and present the unfinished boxes in the proper position to the upper box finishing tool sections, especially the adhesive nozzles and the upper folding tool section. The horizontal adjustability on the other hand makes it possible in a simple way to package two articles or two stacks of articles next to one another on a single blank bottom, whereupon the blank is folded and the box finished.